MIM capacitors are commonly integrated into semiconductor chips, and are widely used in analog applications (e.g., filters, amplifiers, alternating current (AC) couplers, resistor-capacitor (RC) clamps, etc.). MIM capacitors are also commonly used as decoupling capacitors (decaps) to filter out power network noise. A MIM capacitor includes two terminals (e.g., metal plates), and a dielectric layer between the terminals. Ideally, the capacitance of the MIM capacitor has little to no dependence on the voltage applied to the MIM capacitor.
In a conventional chip, MIM capacitors are inserted in the back end of line (BEOL) of the chip. The BEOL of the chip comprises multiple metal layers embedded in multiple insulating layers for interconnecting devices in the chip and connecting devices in the chip to contacts for chip-to-package connections. Fabricating MIM capacitors in the BEOL of a chip requires additional masks and process steps, which increase fabrication costs. This may also create schedule delays, and require a technology file difference from the baseline process.